Earthworking tools are extensively used, in conjunction with earthmoving machines, in construction and earthworking operations. The earthworking tools are mounted on a shank or support member and are generally of the replaceable type. Periodical replacement is necessary since the tools are subject to extreme wear due to operation in conditions where they encounter rock, sand, and other types of abrasive earthen materials. In order to expedite the replacement of a worn tool with a new tool, various types of retaining pins have been used to secure the replaceable tool to the supporting member.
In order that minimum time is lost during the replacement of a worn tool, it is desirable that the retaining pin be easily and quickly removable and reinsertable. It is also desirable that the retaining pin be reusable to conserve materials and costs. Also, it is essential that the retaining pin apply a continuous force between the tool and the support member in order to hold the tool in firm contact with the support member.
One type of retaining pin for securing a tooth to an adapter is shown in U.S. Pat. No. 3,685,178, issued to Thomas A. Ratkowski on Aug. 22, 1972. This retaining pin includes a rigid metal member of rectangular cross-sectional shape, another metal member of less massive area, and a layer of resilient material bonded to and between the two metal members. The resilient material is preferably rubber, and in the installed conditions, is under compression to cause the tooth to be drawn up on the adapter.
The retaining pin in the above-identified patent requires considerable effort and time consuming operations to produce. It is composed of two metal parts which require separate machining operations, a rubber part which also requires some type of operation to produce apertures therein, and further requires a bonding operation to bond the various parts together. In view of the fact that the tooth and adapter, which uses the above-described pin, operates in severe earthworking conditions, the pin is subject to all type of environments, including dirt, sand, rock, mud, and water. Under these conditions, it is likely that the rubber member would have a short usable life. In addition, repeated loading or impacting of the tooth can cause deterioration of the rubber, loss of holding force, and possible loss of the tooth from the adapter.
The present invention is directed to overcoming one or more of the problems as set forth above.